Electrochemiluminescence and analytical applications of terbium thiophene carboxylic acid complexes

In this work, the electrogenerated chemiluminescence (ECL) behavior of a lanthanide Tb(III) complex was studied using thiophene carboxylic acid (3-thiophenecarboxylic acid, 3-TCA) as the ligand and triethanolamine (TEOA) as the co-reactant. The spectral features of the ECL and fluorescence (FL) of the Tb(III) complex were analyzed. The complexes were characterized by FT-IR and elemental analyses. The effects of TEOA concentration, pH, and scan rate on the ECL intensity were studied in detail. Furthermore, a simple ECL platform was reported for the sensitive and selective detection of Cr6+ based on quenching after the addition of Cr6+. A method for the detection of Cr6+ with high sensitivity was established, and the limit of detection was determined as 0.064 nM. It is anticipated that these complexes can be a new class of promising materials for fabricating ECL sensors to detect Cr6+ readily in environmental and practical samples.